assign11.aux/CeisQuery.java

   1 import com.sleepycat.db.Environment;
   2 import com.sleepycat.db.EnvironmentConfig;
   3 import com.sleepycat.dbxml.*;
   4
   5 import java.io.File;
   6
   7 public class CeisQuery {
   8
   9     private void run() {
  10         Environment myEnv;
  11         File envHome = new File("xmlEnvironment");
  12         XmlManager myManager = null;
  13         XmlContainer myContainer = null;
  14
  15         try {
  16             /* Create the environment. */
  17             EnvironmentConfig envConf = new EnvironmentConfig();
  18             envConf.setAllowCreate(false);
  19             envConf.setInitializeCache(true);
  20             myEnv = new Environment(envHome, envConf);
  21
  22             /* Create the manager. */
  23             XmlManagerConfig managerConfig = new XmlManagerConfig();
  24             managerConfig.setAdoptEnvironment(true);
  25             myManager = new XmlManager(myEnv, managerConfig);
  26
  27             /* Open the container. */
  28             myContainer = myManager.openContainer("ceis.dbxml");
  29
  30             // Get a query context
  31             XmlQueryContext context = myManager.createQueryContext();
  32             context.setReturnType(XmlQueryContext.LiveValues);
  33             context.setEvaluationType(XmlQueryContext.Eager);
  34
  35             // Declare the query string
  36             String myQuery = "for $s in doc(\"dbxml:ceis.dbxml/ceis.xml\")/ceis/students/student return <studentid>{$s/studentid/string()}</studentid>";
  37             XmlQueryExpression qe = myManager.prepare(myQuery, context);
  38             /* Execute the query. */
  39             XmlResults results = qe.execute(context);
  40
  41             /* Display the results. */
  42             System.out.printf("Count=%d%n", results.size());
  43             XmlValue value = results.next();
  44             while (value != null) {
  45                 /* Get the xml returned by query. */
  46                 String result = value.asString();
  47
  48                 /* Debug output. */
  49                 System.out.printf("result= %s%n", result);
  50
  51                 /* Get the next value returned by the query. */
  52                 value = results.next();
  53             }
  54
  55             /* Cleanup. */
  56             results.delete();
  57             qe.delete();
  58
  59         } catch (Exception e) {
  60             e.printStackTrace();
  61         } finally {
  62             /* Close the container and the manager (manager closes environment). */
  63             try {
  64                 if (myContainer != null) {
  65                     myContainer.close();
  66                     System.out.println("Container closed.");
  67                 }
  68                 if (myManager != null) {
  69                     myManager.close();
  70                     System.out.println("Manager closed.");
  71                 }
  72                 System.out.println("End of program.");
  73             } catch (XmlException ce) {
  74                 ce.printStackTrace();
  75             }
  76         }
  77     }
  78
  79     public static void main(String[] args) {
  80         CeisQuery application = new CeisQuery();
  81         application.run();
  82     }
  83 }